Toggle wrench having automatic abutment adjusting means



July 26, 1966 R. w. WELLER TOGGLE WRENCH HAVING AUTOMATIC ABUTMENT ADJUSTING MEANS 2 Sheets-Sheet 1 Filed March 27, 1964 INVENTOR. ROBERT W. WELLER 2 BYZUMWML July 26, 1966 R. W. WELLER TOGGLE WRENCH HAVING AUTOMATIC ABUTMENT ADJUSTING MEANS 2 Sheets-Sheet 2 Filed March 27, 1964 FIG. 7 55 54 INVENTQR. ROBERT W. WELLER h/M M United States Patent Robert This invention realtes generally to workpiece clamping devices such as wrenches. More specifically it relates to wrenches having jaws adapted to close upon a workpiece in response to relative closing movement of wrench handles, the improvement afforded by the invention having to do with automatic locking of the jaws upon different size workpieces without requiring separate adjustment shifting of the locking structure to compensate for different size workpieces.

The specific improvement referred to above is lacking in wrenches described in Us. Patents 2,280,001 to Peterson and 2,514,130 to Jones; however, it is needed in wrenches of this type since a user. must use both hands to separately adjust the locking structure to compensate for different size worlcp ieces each time he uses the wrench. While not being confined to the specific type wrenches disclosed in said patents, the present invention does supply the need there existing since a user need not concern himself with the workpiece size, but merely uses' the wrench with one hand, and the wrench itself self-compensates to accommodate different size workpieces.

It is a major object of the invention to meet the need for a self-compensating wrench through the provision of a novel combination of elements that includes a linkage characterized as of the four-bar type, work clamping jaws on the first and second bars, handles on the second and fourth bars, the third bar being (free to translate at and relative to the second bar in response to handle closingmovement tending to effect closing of the jaws, and means for blocking the third bar translation in response to handle closing movement. specifically, third bar translation is automatically blocked at a predetermined. time following closing of the jaws upon a workpiece andafter'the handles are closed together sufiiciently that a toggle connection between the third and fourth bans is ready to undergo over-center movement relative to said bars. Such permitted translation of the third bar relative to the second bar allows the parts to move the distance required to bring them into predetermined position to undergo so-called lockup, the parts in effect over-riding the fixed positioning of the jaws on the first and second bars, which fixed positioning may vary due to jaw engagement with different sized workpieces.

Other objects of the invention include the provision of a spring carried to yieldably resist third bar translation with sufficient force that the jaws are closable on a workpiece; the provision of a novel clutch having third bar translation blocking and unblocking position, and a novel clutch actuator carried to actuate the clutch from unbloclcing to blocking position at said predetermined time.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following detailed description of the drawings, in which:

FIG. 1 is a side elevation with the tool in work clamp- More FIG. 4 is a cut-away showing of the lock-up disc gripping principle;

FIG. 5 is a fragmentary section taken on line 5-5 of FIG. 1;

FIG. 6 is a side elevation of the actuating mechanism for the lock up system, in unlocked position;

FIG. 7 is a fram'entary section taken on line 77 of FIG. 6;

FIG. 8 is a fragmentary isde elevation of a modified actuating mechanism for the lock up system; and

FIG. 9 is a view showing a slip joint connection at the jaw of the tool to allow gripping of larger workpieces.

Referring first to FIG. 1, the workpiece clamping device basically includes a linkage characterized as of the four-bar type, with typical bar elements indicated at 10, 11, 12 and 13 respectively. Work clamping jaws are shown at 14 and 15 on the first and second bar elements, and handles are provided as at 16 and 17 on extensions of the second and fourth bars respectively.

While pivot connections are provided at 18 between the first and second bar elements, at 19 between the third and fourth bar elements, and at 20 between the fourth and first bar elements, it will be seen that the third bar element 12 is free to translate at and relative to the second bar 11 in response to handle closing movement tending to effect closing of the jaws. Thus, for example, the third bar element 12 has a terminal 21 received in a slot 22 provided in the handle extension 16, the terminal 21 in the FIG. 6 position being free to translate at and relative to the second bar in response to handle closing movement. In this regard, means such as a spring 23 located in the slot 22 is provided to yieldably resist a third bar translation sufficiently that the jaws are closable on a workpiece such as pipe 24 in response to relative closing of the handles.

In accordance with the invention, means is provided for blocking such third bar translation in response to handle closing movement, this novel element being considered a substantial improvement over prior devices of the type with which the invention is concerned, in view of the automatic functioning thereof as the handles are over-center movement.

.closed together. In the arrangement shown, the said means functions to block third bar translation at a predetermined time following closing of the jaws upon a workpiece and after the handles are closed together sufficiently that a toggle connection is ready to undergo A typical toggle connection of this type is provided at the pivot 19, and is adapted to transmit increased closing pressure to the jaw 14 on the first bar 10 as the toggle connection moves forwardly over-center relative to the third and fourth bars. For example, the pivot 19 moves from the position shown in FIG. 6 to the position shown in FIG. 1 as the handles are closed in order to lock the jaws on the workpiece, the axis of the pivot 19 moving over-center or across the line which connects the axis of the pivot 20 to the terrznsinal 21. One such line is drawn in FIG. 6 and labeled More specifically, the means for blocking third bar translation includes a clutch having third bar translation blocking and unblocking positions, and a clutch actuator carried to actuate the clutch from unblocking to blocking position at the mentioned predetermined time. One such clutch found to be of highly advantageous construction, and operating with unusual simplicity in relation to the wrench, comprises a plunger 26 positioned to block third bar translation at and relative to the second bar. As seen in FIG. 2, the plunger is bodily movable by the third bar terminal 21, and in the direction of the arrows 27 relative to the secondbar. The clutch shown may also be considered to include structure carried by center movement.

the second bar to hold the plunger against movement relative thereto in response to actuation of said structure by the clutch actuator. Such plunger gripping structure is illustrated to include a stack28 of washers 29 closely receiving the plunger therethrough for relative sliding movement. The annular portions of the Washers are confined within the tubular handle 16, and they have extensions 30 projecting through a slot 31 in the tubular handle which faces generally the opposite handle 17. Furthermore, the washer extensions 30 are held in stack relationship between a shoulder 32 on the handle 16 and a member 33 biased by the spring 23 toward the washers. The spring is confined between member 33 and a flange 34 on the plunger 26 so as to urge the plunger toward the third bar terminal 21.

In the mentioned blocking position preventing third bar translation, the washers have positions of increased tilt relative to the plunger, whereby their inner edges 35 grip the plunger as before shown in FIG. 4, preventing further axial displacement of the plunger in the direction of the arrow 36. A clutch actuator is provided and carried to actuate the clutch from unblockin-g to blocking position at the mentioned predetermined time. In the example shown, the actuator includes a washer tilting element 37 having a washer portion 38 and a finger 39 connected thereto and projecting in the space between the handles 16 and 17, and also toward the bar 12. The element 37 rocks about the angled terminal 40 of the member 33 so that when displaced clockwise as seen in FIG. 2, the clutch actuator tilts the washers 29 to the positon seen in FIG. 4. -It is also to be noted at this point that when the actuator 37 is released, the spring 23 acts through the member 33 and the washer portion 38 of the actuator 37 to return the washers to the untilted positions seen in FIG. 2, that is, to decrease their tilt relative to the plunger after release by the plunger in response to relative opening movement of the handles. Washer or disc 33 has a lip 133 received in an opening 134 in the handle to anchor and also retain the washer, so that it may cooperate with the spring 23 and discs 28, as described.

The clutch actuator may also be considered to include a trigger 41 carried for bodily movement to engage the washer tilting element 37 in response to relative closing movement of the handles. The trigger 41 typically comprises a lever pivoted at 19 and projecting between the handles 16 and 17 alongside the bar 12. The trigger has a lip 42 turned to extend between a boss 43 on the bar 12 and a release lever 44. Further, the trigger has a lip 45 having sliding engagement with the finger 39, as best seen in FIG. 2. The lip 45 is adapted to slide along the finger 39 without actuating the element 37 to tilt the washers until a predetermined time at which the handles 16 and 17 are sufiiciently close together that the toggle connection 19 is ready to undergo over- At this time, the trigger lip 42 engages the release lever at 44, the release lever engaging the bar at 46, whereby further closing movement of the handles causes the trigger lip 45 to displace the finger 39 clockwise to the position seen in FIG. 1 for locking up the clutch, thereby blocking translation of the bar 12.

At this point it will be noted that the larger the diameter of the workpiece 24, the larger will be the spread between the jaws 14 and 15 when gripping the workpiece, and the greater will be the lost motion translation of the third bar terminal 21 relative to the second bar 11 prior to the predetermined time at which the toggle 19 is ready to undergo over-center movement, and also prior to the time that the translation of the terminal 21 is blocked. Thus, it is seen that the device automatically compensates for diflerent size workpieces while still providing automatic locking of the paws on the workpiece, all in response to handle closing movement.

The purpose of the release lever 44 is to afford release of the jaws and handles from locked-up condition. This is typically effective by providing the release lever extension 50 toward the extension 51 of the handle 17, the pivoting of the release lever at 52 and on the handle 17 being such that leverage is exerted to act via the third bar 12 for effecting reverse displacement of the toggle connection 19 over-center. The invention also contemplates the provision of a spring such as coil spring 53 acting to urge the release lever toward the third bar 12. As seen in FIG. 7, the coil spring turns are wrapped about the pivot pin 54 extending through the channel flanges 55 of the release lever, with opposite turned portions 56 and 57 of the spring respectively engaging the handle 17 to urge the body of the spring and the pivot pin 54 in a direction away from the handle. The pivot connection at 52 is shiftable as accommodated by the curved slots 58 in the flanges 59 of the handle 17 to allow the spring 53 to bodily displace the release lever toward the third bar, as for example is illustrated in FIG. 6.

A thumb screw adjustable stop is provided at 60 to 1 limit the bodily displacement of the release lever toward the third bar, and it will be seen that this arrangement provides for final clamping pressure adjustment for any size workpiece. In this regard, the tension in the coil spring 53 may be made sufficient to cause the release lever 44 to bear against the lip 42 of the trigger 41 with sufficient force as to actuate the clutch washers to tilted position prior to complete displacement of the release lever to the position seen in FIG. 1, i.e., clamped between the lip 42 and the handle 17 at 46. However, in the FIG. 1 position, the pivot pin 54 is displaced around the corner in the slots 58 and sufliciently that the release lever cannot be inadvertently tripped to release the wrench. A return spring is seen at connecting the bars 10 and 11 and tending to open the jaws. Finger 81 integral with handle 17 acts to limit movement of release lever extension away from the handle.

Referring to FIG. 9, an adjustable pivot connection between the bar 10 and the bar 13 is shown to allow the jaws to accommodate a larger range of workpiece sizes. The adjustable connection includes a U-shaped slot 70 in the bar 10 and located to receive the pivot pin 71 in either the position indicated at 71 or an alternate p0sition indicated at 72.

I claim:

1. In a workpiece clamping device, a linkage characterized as of the four-bar type, work clamping jaws on the first and second bars, handles on the second and fourth bars, the third bar being free to translate at and relative to the second bar in response to handle closing movement tending to eflect closing of the jaws, and means operable independently of said third bar translation for blocking said third bar translation in response to said handle closing movement.

2. In a workpiece clamping device, a linkage characterized as of the tour-bar type, work clamping jaws on the first and second bars, handles on the second and fourth bars, the third bar being free to translate at and relative to the second bar in response to handle closing movement tending to effect closing of the jaws, means to yieldably resist said third bar translation sufficiently that the jaws are closable on a workpiece in response to relative closing of the handles, and means operable independently of said third bar translation for blocking said third bar translation in response to said handle closing movement.

3. In a workpiece clamping device, a linkage characterized as of the four-bar type, work clamping jaws on the first and second bars, handles on the second and fourth bars, the third bar being free to translate at and relative to the second bar in response to handle closing movement tending to eflect closing of the jaws, the linkage including a toggle connection between the third and fourth bars which is adapted to transmit increased closactuator carried to actuate the clutch from unblocking to blocking position at said predetermined time, said actuator including a trigger lever operable independently of third bar translation.

4. The device as defined in claim 3 including a spring carried to yieldably resist said third bar translation at the second bar with suflicient force that the jaws are closable on a workpiece in response to relative closing of the handles.

5. The device as defined in claim 3 in which said clutch comprises a plunger positioned to block said third bar translation at and relative to the second bar, the

plunger being bodily movable by the third bar, and relative to the second bar, and structure carried by the second bar to hold the plunger against movement relative thereto in response to actuation of said structure by the clutch actuator.

6. The device as defined in claim 5 in which said plunger gripping structure includes a stack of washers closely receiving the plunger for relative sliding move- .ment, the washers having positions of increased tilt relative to the plunger in said blocking position, the washers being blocked from translation in response to third bar translation.

7. The device as defined in claim 6 in which the clutch actuator includes a washer tilting element carried by the second bar and a trigger carried for bodily movement to engage said element in response to relative closing movement of the handles, thereby to efiect tilting of the washers to said positions of increased tilt relative to the plunger.

8. The device as defined in claim 6 in which the plunger and washers are confined within the handle on the second bar.

9. The device as defined in claim 6 including means to decrease the tilt of the washers relative to the plunger in order to release the plunger in response to relative opening movement of the handles,

10. The device as defined in claim 6 including a release lever pivoted on the fourth bar to exert leverage acting via the third bar to effect reverse displacement of the toggle connection over-center for releasing the jaws from the workpiece, and a spring acting to urge the release lever toward the third bar.

11. The device as defined in claim 10 in which the release lever and fourth bar have a shiftable pivot connection allowing said release lever urging spring to bodily displace the release lever toward the third bar, and including an adjustable stop to limit said bodily displacement of the release lever toward the third bar and thereby control the blocking of said third bar translation.

12. In a workpiece clamping device, a pair of jaws, means including linkage bars and a pair of handles on two of the bars for closing the jaws and having a first range of relative movement in which the jaws are closable into engagement with a workpiece and having a second range of relative movement in which the workpiece engaging jaws become locked against release from the workpiece, said bars including a third bar free to translate relative to one of said two bars in response to handle closing movement, and other means responsive to attempted further closing of the handles after the jaws engage the workpiece to initiate relative movement of the handles in said second range of relative movement, whereby the jaws may be locked onto different size workpieces merely in response to relative closing movement of the handles, said other means including structure operable independently of translation of the third bar for blocking translation thereof in response to handle closing movement.

References Cited by the Examiner UNITED STATES PATENTS 2,499,201 2/ 1950 Thayer 813 2,514,130 7/1950 Jones 81370 2,523,385 9/1950 Mead 81370 3,116,656 1/1964 Hostetter 81379 FOREIGN PATENTS 642,102 6/ 1962 Canada. 1,100,105 3/1955 France.

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. IN A WORKPIECE CLAMPING DEVICE, A LINKAGE CHARACTERIZED AS OF THE FOUR-BAR TYPE, WORK CLAMPING JAWS ON THE FIRST AND SECOND BARS, HANDLES ON THE SECOND AND FOURTH BARS, THE THIRD BAR BEING FREE TO TRANSLATE AT AND RELATIVE TO THE SECOND BAR IN RESPONSE TO HANDLE CLOSING MOVEMENT TENDING TO EFFECT CLOSING OF THE JAWS, AND MEANS OPERABLE INDEPENDENTLY OF SAID THIRD BAR TRANSLATION FOR BLOCKING SAID THIRD BAR TRANSLATION IN RESPONSE TO SAID HANDLE CLOSING MOVEMENT. 